Updated

A helicopter searching for dozens of rebel-held hostages in Peru's Amazon jungle was attacked with gunfire Thursday and a police officer on board was killed and two people were wounded, the Defense Ministry said.

The attack came as the government sent 1,500 soldiers and police to the area near Peru's key Camisea gas field to try to rescue 40 construction workers who were grabbed on Monday by Maoist Shining Path guerrillas. Officials say the rebels have demanded $10 million in ransom.

Gunfire tore through the helicopter as it was patrolling over the district of Echarate, and police Capt. Nancy Flores died, the Defense Ministry said in a statement. It did not say what happened after the shooting or provide information about the identity of the attackers. Those on board the helicopter were part of the recently deployed force.

Mayor Fedia Castro of Convencion municipality, which includes the town where the workers were abducted, told the radio station Radioprogramas that rebels on the ground fired at the helicopter. She said those wounded included an army technician and a civilian guide.

President Ollanta Humala urged the hostages' families to trust in the authorities, and he vowed to capture and prosecute the kidnappers.

"We hope that in a very short time we can resolve the problem, aiming for the cost to be zero," Humala told reporters before news of the shooting emerged.

Local officials have said the workers were kidnapped in the hamlet of Kepashiato, near the country's main natural gas field in the Amazon jungle. Those who were abducted were working as contractors on gas industry projects.

"The government doesn't negotiate with terrorists," Justice Minister Juan Jimenez said Thursday in an interview with Panamericana Television.

The Defense Ministry said in a statement Wednesday night that 1,500 soldiers and police were involved in the search and rescue operation.

The abducted Peruvian workers, who began building a new gas treatment plant last year, were rounded up about 3 a.m. Monday from their hotels, Kepashiato's mayor, Rosalio Sanchez, has said. The mayor said the rebels lingered for three hours, buying groceries and summoning about 20 residents to an assembly where they condemned the government and the natural gas industry.

Sanchez said people in the town fear the rebels could return and that as of Thursday there were no soldiers or police in the town.

"They could come back at any time. There's no protection," Sanchez told The Associated Press by phone.

Among the kidnapped workers, 29 were employees of the construction company Skanska of Sweden.

"There's not that much I can say in regard to their safety. We're cooperating with our client and the authorities there," said Edvard Lind, Skanska's spokesman in Sweden.

As for the company's future projects in Peru, he said: "We see big opportunities in Peru, but right now we're focusing on getting our colleagues released."

Such mass abductions are rare in Peru, and this week's kidnapping showed a new brazenness from the Shining Path.

The cocaine-trade funded rebel band is a small remnant of the Maoist group that terrorized Peru in the 1980s and 1990s. It is believed to number about 300 to 500 fighters and is centered in the Ene and Apurimac Valley region where more than half of Peru's coca crop is grown. The town where the kidnapping occurred is located in an adjacent region.